An interaction between the renin-angiotensin-aldosterone system (RAAS) and fibrinolytic system has been postulated to be related w/an increased risk of cardiovascular events due to the activation of the RAAS. The purpose of the present study is to test the hypotheses that aldosterone increases PAI-1 syntheses in humans. SPECIFIC AIMS: 1) To test the hypothesis that aldosterone increases PAI-1 by comparing the effects of placebo, the thiazide diuretic hydrochlorothiazide and the aldosterone receptor antagonist spironolactone on fibrionolytic balance in hypertensive subjects. 2) To determine whether specific aldosterone receptor antagonism, like ACE inhibition, improves endothelial function in patients w/hypertension.